\\[-1.8ex] Soil Heterogeneity & 0.735$^{**}$ & 0.828$^{***}$ & 0.769$^{***}$ & 0.661$^{**}$ & 0.516$^{**}$ & 0.556$^{***}$ \\ 
  & (0.357) & (0.259) & (0.277) & (0.285) & (0.222) & (0.216) \\ 
  & & & & & & \\ 
\\[-1.8ex] 
Observations & 23,254 & 23,254 & 23,254 & 23,254 & 23,254 & 23,215 \\ 
R$^{2}$ & 0.007 & 0.342 & 0.355 & 0.365 & 0.392 & 0.403 \\ 
